Engineered photosynthesis demonstrated in animals in vivo via synthetic biology
nature.com
nature.com
Slightly related - this study reminds me of an Andy Weir short story Antihypoxiant - http://www.galactanet.com/oneoff/antihypoxiant.html.
based on those good results, they go back to the lab and cook up a general purpose "edit your own genome for free!" project and put all the steps to reproduce it in a github repo. But... after half the world has downloaded and started playing, those burning man people start dying of cancer.
> Our body’s demand for glucose is higher than photosynthesis can accommodate. Associate professor Lindsay Turnbull of the University of Oxford determined that if the surface area of an adult woman contained chlorophyll like a leaf, it would produce only 1% of the daily energy requirements for the person to survive. To live by photosynthesis alone, the woman would need a green body with the surface the size of a tennis court.
A man is about two square meters of skin. Assuming they lay down to photosynthesize most efficiently from perpendicular sun rays that would be one square meter, so 1400 watts. You would need an ~11% efficient conversion to meet the needs of a human. Plants currently top out at about 6.4% for highly efficient C4 plants like sugarcane. 11% is the maximum efficiency possible.
>The photosynthetic efficiency is dependent on the wavelength of the light absorbed. Photosynthetically active radiation (400–700 nm) constitutes only 45% of the actual daylight. Therefore the maximum theoretical efficiency of the photosynthesis process is approximately 11%.
Not only would you have to somehow replicate the extreme efficiency of sugarcane on animal skin (an organ with no support structures for photosynthesis), you’d have to double the efficiency.
Sun-fed beef?
Hell, I would buy myself some photosynthesizing cows and pigs if I can just put them in a pen outside and not have to feed them.
The real problem is that you need hemispherical hairless cows. ;)
That's a good opportunity to join forces with Sabine Hossenfelder and together move some of excess funding from, say, particle physics, and allocate it to fundamental research on which all physics depends: creation of frictionless, vacuum-rated spherical cows.
I suspect a photosynthetic cow would still need to eat a lot of grass
If you eat fructose, you end up turning some of that into uric acid and excreting it, wastefully. It does other varied harm on its way out.
That's exactly my point. Some percentage of that ADP and ATP will be lost and the adenine/ribose broken down or reused for something else - cells are messy environments. Some of that will be lost permanently to waste. The more turnover in this process, the more opportunity for that loss.